An airplane is propelled by one or several propulsion assemblies each comprising a turboshaft engine housed in a tubular nacelle. Each propulsion assembly is attached to an aircraft by a mast situated under a wing or at the fuselage.
A nacelle generally has a structure comprising an air intake upstream of the engine and a middle section capable of surrounding a fan of the turboshaft engine, a downstream section housing thrust reverser means and able to surround the combustion chamber of the turboshaft engine. The nacelle ends with a jet nozzle whereof the outlet is situated downstream of the turboshaft engine.
The air intake comprises, on one hand, an air intake lip adapted to allow optimal collection towards the turboshaft engine of the air necessary to supply the fan and internal compressors of the turboshaft engine, and on the other hand, a downstream structure, on which the air intake lip is attached, intended to suitably channel the air towards the blades of the fan. The assembly is attached upstream of the fan case belonging to the upstream section of the nacelle.
In flight, depending on the temperature and moisture conditions, ice can form on the nacelle, in particular at the outer surface of the air intake lip. The presence of ice or frost modifies the aerodynamic properties, which disrupts the conveyance of the air towards the fan.
In order to resolve this problem, it is known to integrate the deicing system in a composite skin that is then perforated in order to obtain at least one fastening hole or a multitude of acoustic holes. The panel perforated with a multitude of acoustic holes forms an acoustic panel able to absorb the noises generated by the operation of the turboshaft engine.
However, the deicing system is generally not visible during the piercing, which causes a significant risk of piercing the resistive elements. Such damage, which is difficult to detect, has the consequence of breaking the continuity of the deicing performance.